/* crypto/lhash/lhash.c */

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

  * All rights reserved.

  *

  * This package is an SSL implementation written

  * by Eric Young (eay@cryptsoft.com).

  * The implementation was written so as to conform with Netscapes SSL.

  * 

  * This library is free for commercial and non-commercial use as long as

  * the following conditions are aheared to.  The following conditions

  * apply to all code found in this distribution, be it the RC4, RSA,

  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

  * included with this distribution is covered by the same copyright terms

  * except that the holder is Tim Hudson (tjh@cryptsoft.com).

  * 

  * Copyright remains Eric Young's, and as such any Copyright notices in

  * the code are not to be removed.

  * If this package is used in a product, Eric Young should be given attribution

  * as the author of the parts of the library used.

  * This can be in the form of a textual message at program startup or

  * in documentation (online or textual) provided with the package.

  * 

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  * 1. Redistributions of source code must retain the copyright

  *    notice, this list of conditions and the following disclaimer.

  * 2. Redistributions in binary form must reproduce the above copyright

  *    notice, this list of conditions and the following disclaimer in the

  *    documentation and/or other materials provided with the distribution.

  * 3. All advertising materials mentioning features or use of this software

  *    must display the following acknowledgement:

  *    "This product includes cryptographic software written by

  *     Eric Young (eay@cryptsoft.com)"

  *    The word 'cryptographic' can be left out if the rouines from the library

  *    being used are not cryptographic related :-).

  * 4. If you include any Windows specific code (or a derivative thereof) from 

  *    the apps directory (application code) you must include an acknowledgement:

  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

  * 

  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

  * SUCH DAMAGE.

  * 

  * The licence and distribution terms for any publically available version or

  * derivative of this code cannot be changed.  i.e. this code cannot simply be

  * copied and put under another distribution licence

  * [including the GNU Public Licence.]

  */

 /* Code for dynamic hash table routines

  * Author - Eric Young v 2.0

  *

  * 2.2 eay - added #include "crypto.h" so the memory leak checking code is

  *	     present. eay 18-Jun-98

  *

  * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98

  *

  * 2.0 eay - Fixed a bug that occurred when using lh_delete

  *	     from inside lh_doall().  As entries were deleted,

  *	     the 'table' was 'contract()ed', making some entries

  *	     jump from the end of the table to the start, there by

  *	     skipping the lh_doall() processing. eay - 4/12/95

  *

  * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs

  *	     were not being free()ed. 21/11/95

  *

  * 1.8 eay - Put the stats routines into a separate file, lh_stats.c

  *	     19/09/95

  *

  * 1.7 eay - Removed the fputs() for realloc failures - the code

  *           should silently tolerate them.  I have also fixed things

  *           lint complained about 04/05/95

  *

  * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92

  *

  * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992

  *

  * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91

  *

  * 1.3 eay - Fixed a few lint problems 19/3/1991

  *

  * 1.2 eay - Fixed lh_doall problem 13/3/1991

  *

  * 1.1 eay - Added lh_doall

  *

  * 1.0 eay - First version

  */

 #include <stdio.h>

 #include <string.h>

 #include <stdlib.h>

 #include <openssl/crypto.h>

 #include <openssl/lhash.h>

 const char lh_version[]="lhash" OPENSSL_VERSION_PTEXT;

 #undef MIN_NODES 

 #define MIN_NODES	16

 #define UP_LOAD		(2*LH_LOAD_MULT) /* load times 256  (default 2) */

 #define DOWN_LOAD	(LH_LOAD_MULT)   /* load times 256  (default 1) */

 static void expand(LHASH *lh);

 static void contract(LHASH *lh);

 static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash);

 EXPORT_C LHASH *lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c)

 	{

 	LHASH *ret;

 	int i;

 	if ((ret=(LHASH *)OPENSSL_malloc(sizeof(LHASH))) == NULL)

 		goto err0;

 	if ((ret->b=(LHASH_NODE **)OPENSSL_malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)

 		goto err1;

 	for (i=0; i<MIN_NODES; i++)

 		ret->b[i]=NULL;

 	ret->comp=((c == NULL)?(LHASH_COMP_FN_TYPE)strcmp:c);

 	ret->hash=((h == NULL)?(LHASH_HASH_FN_TYPE)lh_strhash:h);

 	ret->num_nodes=MIN_NODES/2;

 	ret->num_alloc_nodes=MIN_NODES;

 	ret->p=0;

 	ret->pmax=MIN_NODES/2;

 	ret->up_load=UP_LOAD;

 	ret->down_load=DOWN_LOAD;

 	ret->num_items=0;

 	ret->num_expands=0;

 	ret->num_expand_reallocs=0;

 	ret->num_contracts=0;

 	ret->num_contract_reallocs=0;

 	ret->num_hash_calls=0;

 	ret->num_comp_calls=0;

 	ret->num_insert=0;

 	ret->num_replace=0;

 	ret->num_delete=0;

 	ret->num_no_delete=0;

 	ret->num_retrieve=0;

 	ret->num_retrieve_miss=0;

 	ret->num_hash_comps=0;

 	ret->error=0;

 	return(ret);

 err1:

 	OPENSSL_free(ret);

 err0:

 	return(NULL);

 	}

 EXPORT_C void lh_free(LHASH *lh)

 	{

 	unsigned int i;

 	LHASH_NODE *n,*nn;

 	if (lh == NULL)

 	    return;

 	for (i=0; i<lh->num_nodes; i++)

 		{

 		n=lh->b[i];

 		while (n != NULL)

 			{

 			nn=n->next;

 			OPENSSL_free(n);

 			n=nn;

 			}

 		}

 	OPENSSL_free(lh->b);

 	OPENSSL_free(lh);

 	}

 EXPORT_C void *lh_insert(LHASH *lh, void *data)

 	{

 	unsigned long hash;

 	LHASH_NODE *nn,**rn;

 	void *ret;

 	lh->error=0;

 	if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))

 		expand(lh);

 	rn=getrn(lh,data,&hash);

 	if (*rn == NULL)

 		{

 		if ((nn=(LHASH_NODE *)OPENSSL_malloc(sizeof(LHASH_NODE))) == NULL)

 			{

 			lh->error++;

 			return(NULL);

 			}

 		nn->data=data;

 		nn->next=NULL;

 #ifndef OPENSSL_NO_HASH_COMP

 		nn->hash=hash;

 #endif

 		*rn=nn;

 		ret=NULL;

 		lh->num_insert++;

 		lh->num_items++;

 		}

 	else /* replace same key */

 		{

 		ret= (*rn)->data;

 		(*rn)->data=data;

 		lh->num_replace++;

 		}

 	return(ret);

 	}

 EXPORT_C void *lh_delete(LHASH *lh, const void *data)

 	{

 	unsigned long hash;

 	LHASH_NODE *nn,**rn;

 	void *ret;

 	lh->error=0;

 	rn=getrn(lh,data,&hash);

 	if (*rn == NULL)

 		{

 		lh->num_no_delete++;

 		return(NULL);

 		}

 	else

 		{

 		nn= *rn;

 		*rn=nn->next;

 		ret=nn->data;

 		OPENSSL_free(nn);

 		lh->num_delete++;

 		}

 	lh->num_items--;

 	if ((lh->num_nodes > MIN_NODES) &&

 		(lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))

 		contract(lh);

 	return(ret);

 	}

 EXPORT_C void *lh_retrieve(LHASH *lh, const void *data)

 	{

 	unsigned long hash;

 	LHASH_NODE **rn;

 	void *ret;

 	lh->error=0;

 	rn=getrn(lh,data,&hash);

 	if (*rn == NULL)

 		{

 		lh->num_retrieve_miss++;

 		return(NULL);

 		}

 	else

 		{

 		ret= (*rn)->data;

 		lh->num_retrieve++;

 		}

 	return(ret);

 	}

 static void doall_util_fn(LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func,

 			  LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg)

 	{

 	int i;

 	LHASH_NODE *a,*n;

 	/* reverse the order so we search from 'top to bottom'

 	 * We were having memory leaks otherwise */

 	for (i=lh->num_nodes-1; i>=0; i--)

 		{

 		a=lh->b[i];

 		while (a != NULL)

 			{

 			/* 28/05/91 - eay - n added so items can be deleted

 			 * via lh_doall */

 			n=a->next;

 			if(use_arg)

 				func_arg(a->data,arg);

 			else

 				func(a->data);

 			a=n;

 			}

 		}

 	}

 EXPORT_C void lh_doall(LHASH *lh, LHASH_DOALL_FN_TYPE func)

 	{

 	doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL);

 	}

 EXPORT_C void lh_doall_arg(LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg)

 	{

 	doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg);

 	}

 static void expand(LHASH *lh)

 	{

 	LHASH_NODE **n,**n1,**n2,*np;

 	unsigned int p,i,j;

 	unsigned long hash,nni;

 	lh->num_nodes++;

 	lh->num_expands++;

 	p=(int)lh->p++;

 	n1= &(lh->b[p]);

 	n2= &(lh->b[p+(int)lh->pmax]);

 	*n2=NULL;        /* 27/07/92 - eay - undefined pointer bug */

 	nni=lh->num_alloc_nodes;

 	for (np= *n1; np != NULL; )

 		{

 #ifndef OPENSSL_NO_HASH_COMP

 		hash=np->hash;

 #else

 		hash=lh->hash(np->data);

 		lh->num_hash_calls++;

 #endif

 		if ((hash%nni) != p)

 			{ /* move it */

 			*n1= (*n1)->next;

 			np->next= *n2;

 			*n2=np;

 			}

 		else

 			n1= &((*n1)->next);

 		np= *n1;

 		}

 	if ((lh->p) >= lh->pmax)

 		{

 		j=(int)lh->num_alloc_nodes*2;

 		n=(LHASH_NODE **)OPENSSL_realloc(lh->b,

 			(int)(sizeof(LHASH_NODE *)*j));

 		if (n == NULL)

 			{

 /*			fputs("realloc error in lhash",stderr); */

 			lh->error++;

 			lh->p=0;

 			return;

 			}

 		/* else */

 		for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */

 			n[i]=NULL;			  /* 02/03/92 eay */

 		lh->pmax=lh->num_alloc_nodes;

 		lh->num_alloc_nodes=j;

 		lh->num_expand_reallocs++;

 		lh->p=0;

 		lh->b=n;

 		}

 	}

 static void contract(LHASH *lh)

 	{

 	LHASH_NODE **n,*n1,*np;

 	np=lh->b[lh->p+lh->pmax-1];

 	lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */

 	if (lh->p == 0)

 		{

 		n=(LHASH_NODE **)OPENSSL_realloc(lh->b,

 			(unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));

 		if (n == NULL)

 			{

 /*			fputs("realloc error in lhash",stderr); */

 			lh->error++;

 			return;

 			}

 		lh->num_contract_reallocs++;

 		lh->num_alloc_nodes/=2;

 		lh->pmax/=2;

 		lh->p=lh->pmax-1;

 		lh->b=n;

 		}

 	else

 		lh->p--;

 	lh->num_nodes--;

 	lh->num_contracts++;

 	n1=lh->b[(int)lh->p];

 	if (n1 == NULL)

 		lh->b[(int)lh->p]=np;

 	else

 		{

 		while (n1->next != NULL)

 			n1=n1->next;

 		n1->next=np;

 		}

 	}

 static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash)

 	{

 	LHASH_NODE **ret,*n1;

 	unsigned long hash,nn;

 	LHASH_COMP_FN_TYPE cf;

 	hash=(*(lh->hash))(data);

 	lh->num_hash_calls++;

 	*rhash=hash;

 	nn=hash%lh->pmax;

 	if (nn < lh->p)

 		nn=hash%lh->num_alloc_nodes;

 	cf=lh->comp;

 	ret= &(lh->b[(int)nn]);

 	for (n1= *ret; n1 != NULL; n1=n1->next)

 		{

 #ifndef OPENSSL_NO_HASH_COMP

 		lh->num_hash_comps++;

 		if (n1->hash != hash)

 			{

 			ret= &(n1->next);

 			continue;

 			}

 #endif

 		lh->num_comp_calls++;

 		if(cf(n1->data,data) == 0)

 			break;

 		ret= &(n1->next);

 		}

 	return(ret);

 	}

 /* The following hash seems to work very well on normal text strings

  * no collisions on /usr/dict/words and it distributes on %2^n quite

  * well, not as good as MD5, but still good.

  */

 EXPORT_C unsigned long lh_strhash(const char *c)

 	{

 	unsigned long ret=0;

 	long n;

 	unsigned long v;

 	int r;

 	if ((c == NULL) || (*c == '\0'))

 		return(ret);

 /*

 	unsigned char b[16];

 	MD5(c,strlen(c),b);

 	return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24)); 

 */

 	n=0x100;

 	while (*c)

 		{

 		v=n|(*c);

 		n+=0x100;

 		r= (int)((v>>2)^v)&0x0f;

 		ret=(ret<<r)|(ret>>(32-r));

 		ret&=0xFFFFFFFFL;

 		ret^=v*v;

 		c++;

 		}

 	return((ret>>16)^ret);

 	}

 EXPORT_C unsigned long lh_num_items(const LHASH *lh)

 	{

 	return lh ? lh->num_items : 0;

 	}